Rebuilding of a city office block just behind the Bank of England has opened up an opportunity for the Museum of London to unpack their trowels and tape measures and have a look at what lies beneath.

And on Saturday morning, a chance for the public to gawp at their work.

The site is a potentially interesting one as it includes a length of the Walbrook stream, and they have found evidence of Roman era buildings lining the stream, and possibly later wooden structures.

It’s a site that thanks to the Walbrook making it rather wet wasn’t heavily developed until around the 16th century, so the Roman remains are unusually good, or at least were until a modern building was plonked on the site and foundations rammed throughout the site.

The Museum of London have been working on the site for a few years, and excavations have produced evidence for industry and manufacturing in both the Roman and medieval periods. The work also uncovered leather fragments, glass residue and the remains of a possible pottery kiln.

The archaeologists found a total of four timber Roman buildings in two trenches. One building had five rooms and a corridor running along one side; to the north of this were some steps, leading down an alleyway in the direction of the Walbrook, and on the other side was a second building which had four rooms.

It’s thought that these buildings represent workshops, rather than houses, although it was common for craftsmen and their families to work and live on the same premises.

The earliest phases of these buildings appeared to date to the late 1st century at an early stage in the history of Londinium. The evidence shows that, although the area was marshy because of the Walbrook Valley, people were successfully controlling the effects of the water.